Automatic stoker



QUSDAHL Oct. 30

MATIC STOKER 4 Sheets-sh 1 Filed Nov. 27, 1920 A OEYS INVENTOR @cfi. 3Q 1923.

A. OUSDAHL AUTOMATIC STOKER Filed Nov. 27, 1920 4 Sheets-Sheet 2 Get. 3.0 1923.

A. OUSDAHL AUTOMATLC STOKER Filed Nov. 27, 1920 4 Sheets-Sheet 5 I g. 3 /{0/?/V4/ FRO/ 7 ara/ .3

ai do Oct. 30 1923.

A. OUSDAHL AUTOMATIG STOKER' Filed Nov. 27 1920 4 Sheets-Sheet 4 65 (jea INVENTOR fidogm Owdalzl BY N35 Q Q VC' Patented 0a. 30, 1923."

1,4ii2s0 .ADOLPH OUSDAHL, OF SEATTLE, WASHINGTON.

AUTOMATIC STOKER.

Application filed November 27, 1920. Serial No. 426,735.

To all whom it may concern.

Be it known that I. AnoLrIi OI'SDAHL, a citizen of the United States. and resident of the city of Seattle. in the county of King and State of Washington, have invented certain new and useful Improvements in Automatic Stoker's, of which the following is a specification.

My invention relates to automatic stokers and comprises particularly means for controlling such stokers.

The general object of my invention is to provide means which will regulate such stokers either directly or indirectly through the heat of the furnace fed by the Stoker, or of the building heated thereby,- to maintain an even temperature.

In connection with this general object it is my object to provide a fuel vfeed device and an automatically variable drive mechanism therefor.

It is another object of my invention to provide heat-controlled means for automatically stopping the driving motor or for starting it again, between predetermined temperature limits; which means may be regulated to vary the temperature limits.

Another object is to provide means for regulating and controlling the draft to the furnace in accordance with the temperature which it is desired to maintain.

Another object is to provide a driving means for automatic stokers which will be silent andyet effective in operation.

Another object of my invention is to provide means, in connection with automatic stokers employing a feed hopper. for agitating the fuel therein and for urging it. to wardthe delivery opening of the hopper.

Other objects may be ascertained by a study of the following description and claims.

In the accompanying drawings T have shown my invention in a'form which is now ln'eferred by me.

Figure l is an elevation of my stokcr. parts being broken away.

Figure 2 is an elevation of the stoker from the opposite side, parts being shown in section.

Figijire 3 is a section through my device taken approximately upon the line of the main bearings.

Figure 4 is a section on line -1-4 of Figure 1 illustrating the main reduction gearing.

Figure .5 is an elevation of the variable drive mechanism.

Figure 6 is a diagram of a slightly different control means.

Figure 7 is an elevation of a heat-control device which I prefer to employ.

Essentially my stoker, in common with many others. includes a piston 1 reciproeable within a cylinder 10 by suitable driving mechanism. At one side the cylinder is open to a suitable storage bin or hopper 1 1 which contains the fuel supply, and at one end it is open toward the furnace, into which the fuel is forced through the opening 12 by the piston 1. A connecting rod 13 connects the piston l with a crank 14 which'forms art of or which is secured upon the shaft 15.

The driven gear-16 is preferably connected to a boss or collar 17 keyed upon the shaft 15 by means of. a shear pin 18, although this shear pin connection may be omitted if desired and the gear 16 may then be keyed directly upon the shaft 15. This gear is connected through a variable speed mechanism, designated in general by thenumeral 2. and which is driven through an oscillating shaft 20 and through suitable reduction gearing to a suitable motor 3. This gearing designated in general by the numeral 30, and illustrated in detail in Figure 4, comprises a pinion 30 keyed to the same shaft as the pulley 30 over which the belt 31 from the motor 3 passes; a gear 30 with which the pinion 30 n'ieshes; a pinion 30 on the same shaft as gear 30, -meshing with a gear 30 upon whose shaft is secured the crank arm 32. whereby the crank arm is slowly rotated. This rotating crank 32. which is driven from the r'notor 3 through the gearing 30, is connected to a crank arm on the oscillating shaft. 20. by means of a link 34. The length of the crank arm 33 being greater than the length of the arm 32. the former crank arm 33 will be oscillated by the rotation of the latter crank arm 32. 'hile this is my preferred driving connection. it is evident that any other suitable form may be employed and I do not desire to limit myself to the exact construction described. my purpose being only to secure continuous oscillation of the crank arm The variable speed mechanism which I have shown and which I prefer to employ includes a ratchet wheel 21 and a dog 22 adapted to mesh therewith, The dog 22 is .tercept manner,

carried upon the end of a crank 23 which is secured upon the shaft 20 and which is continuously oscillated thereby. the arm 23 would cause thedog 22 to engage with the wheel 21 at each stroke and to advance the wheel an amount equal to its stroke, ifthere were nothing to vary the engagement of the dog and wheel.

'However, in order to vary the engagement of these two ratchet members, I employ a shield which may be positioned tomthe dog 22 for a, portion of its stroke. This shield is shown herein as a segment disk 24 of slightly greater radius than, the ratchet wheel 21 and positioned closely alongside'of the ratchet wheel. 'The ratchet wheel is freely rotatable upon the shaft 20 and is connected to a gear 25 meshing with the driven gear 16. The shield 24 is freely rotatable, preferably concentric with the ratchet wheel 21, and its periphery is movable into and out of the path of the dog 22. It may be positioned to intercept the engagement of the dog with the ratchet wheel during'any portion of its stroke from no engagement up to engagement during the full stroke.

This is done by oscillating the shield 24 to bring more or less of its periphery within the path of movement of the dog 22. It is obvious, as may be seen in Figure 5, that when the shield 24 is in the path of movement of the dog 22 the latter may not engage the ratchet wheel until its stroke has carried it beyond the forward edge of the shield, as may be seen in dotted lines in the figure referred to. The oscillation of the shield 24 is accomplished in some suitable as through an arm 26 connected thereto and oscillated by a control means to be described later.

In'order to cause the ratchet device to .01)- erate silently, I provide in a boss 27 forming a part of the spring-pressed plunger 28 projecting approximately radiallyinward. The plunger 28 is positioned to contact always with a continuous ring 29 mounted concentrically upon the shaft 20.. During the drive Stroke of the dog 22 the slight friction between the plunger 28 and the periphery of the ring 29 causes the dog 22 to be thrown forward 'into position to engage with the ratchet wheel 21, except, as it may be intercepted by the shield 24. At the beginning of the reverse stroke of the dog, the friction of the plunger 28 and ring 29 causes the dog to be rocked upon 1 it pivot so that it lifts directly upward out being shown as mounted within the of engagement with the wheel 21 and is carried back to the beginning of its stroke in this position, owing to the friction between the plunger and ring referred to.

To assist in the combustion in the furnace I may provide a draft fan or blower, this casing 4 Oscillation of if ratchet dog 22, a small" and rotatable directly upon the'motor shaft. Air is delivered through a duct 40, and at a suitable point a damper 41 is positioned, which may be turned to control or cut off the air delivered to the furnace.

The control means for my stoker may be any that are found suitable. These should be operablethrough the temperature of the building heated by the furnace. As one means ofv accomplishing this control indirectly through the building temperature, I have illustrated a metallic steam bellows 5 which is connected-through a pipe 50 with steam delivered to the heating coils of-the building. The volume of the steam expands directly as its temperature increases. xpansion of the steamwithin the bellows 5, due to increase in temperature, causes the tilting of a lever 51 pivoted at 52 in the frame surrounding the bellows 5 and fulthe specific form of this controlforms nopart of my invention, it is not believed to be necessary to describe it more fully- Control links 54 and 55 depend from opposite ends of the lever 51'. One of these links, as 54, may be connected through a suitable arm 45 to operate the damper 41 controlling the draft. The other link, as 55, may be connected through a bell crank lever 56 and link 57, or other suitable means, to oscillate the arm 26 controlling the variable feed device. or 55, herein shown as the link 54, may be connected to a motor cut out device 6 which controls the starting and stopping of themotor 3, through a suitable connection, as collars 58 adjustably positioned thereupon and operating a bell crank lever 59, which is in turn connected to portions of the cut out device 6. Y

The cut out device 6 shown consists essentially of a circuit breaker switch of any ordinary. type. That shown in Figure 2 consists briefly in a solenoid 60 operable to make or break both the main line switch 61 Either one of these links 54 I and the switch 62. A second switch 63 is occurs-when the temperature of the building is lowered. The reverse operation is identical, and occurs whenthe temperature becomes too great. A line-switch 66 may be employed in addition to that already described.

In figure 6 I have illustrated a thermostatic control means whereby a thermostatic bar 68, which may be placed directly in the room the temperature of which it is desired to control, will operate the solenoid 60 in the manner described. In effect the thermostatic bar 68 takes the place of the switch arm 63. A transformer 69 may be employed to energize the thermostatic control circuit.

To agitate the fuel in the hopper 11 I may provide a rod 7 which is reciprocable therein near its inclined bottom and which carries agitators 70, so shaped as to force the coal downward toward the delivery opening. Reciproca-tion of the rod.7 may be accomplished by any suitable means, such as the lever 71 to which it is connected by a link 74, and which is oscillated from a connection upon the boss 17 through a long link 72, the lever 71 being longer than the length of the crank upon the boss 17. I may also secure a similar rod 73 to the lower part of the piston 1, extending through the delivery opening, this being provided with agitators or pushers 70.

n alarm mechanism may be employed in connection with the shear pin 18 for sounding an alarm bell 8 in case extraordinary resistance is encountered in the mechanism, such as the shear pin. This is shown herein as consisting of-a contract point 81 secured in the boss 17 and 'a contact plate 82 secured upon and insulated from the gear 16 and normally out of contact with the point 81. The plate 82 is connected to a ring 83 with which a brush 84 continuously contacts and the circuit leads thence to a hell 8 or other alarm device. The return circuit is through the battery 85 and the frame of the stoker. pon breakage of the driving connection between the boss 17 and the gear 16, continued rotation of the gear will bring the contact plate 82 into contact with the point 81 and will cause the sounding of the alarm, indicating that breakage has occurred. All fuelforcing members are immediately held stationary, due to the failure of their drive connection.

.In ordinary operation the constant speed motor 3 causes reciprocation of the piston 1, through the belt 31, the gears 30, and the variable speed ratchetdevice 2. The motor also drives the fan within the casing 4 at a constant speed. The agitators 70 are reciprocated from the motor .through the variable speed mechanism 2.

he action of these Various mechanisms is controlled from the thermostat 5. As the temperature increases the links 57 and wheel 21 from the congtant speed, regularly will cause the fracture of 1 tators is reduced. Movement of the link 54 at the same time causes movement of the eed and draft are thus automat- Ordinarily the emerency control collars 5 8 are not brought into operation, but if the usual thermostatic control proves insuflicient to cause the desired change in temperature through regulation of the feeds, these' emergency means are relied upon. In Figure 2, the temperature hadrisen sufiiciently to shut off the motor by contact of the lower collar 58 with the lever 59, and in the position of parts shown the upper collar 58- is about to contact with the lever 59 again to start the motor, the temperature having now fallen.

Proper care in designing the machine for the fuel to be employed will practically eliminate the necessity for an emergency control, as the stoker will regulate itself for any or all temperatures, without supervision. It is unnecessary to set limits manually between which the stoker has free range, for it automatically responds to all temperature changes.

hat I claim as my invention is:

1. In a stoker, a variable feed mechanism including an oscillating arm, a ratchet wheel mounted concentrically therewith. a dog carried by said arm and engageable with said ratchet wheel, and means for depressing said dog into engagement at the start of a stroke and for raising it from engagement at the end thereof.

2. In a stoker, a variable feed mechanism including an oscillating arm, a. ratchet wheel mounted concentrically therewith, a dog carried by said arm and engageable with said ratchet wheel, a ring mounted adiacent to and concentric with said wheels, and a spring-pressed plunger mounted in said dog and engageable with said ring, as and for the purpose described.

3. In a stoker,

tending lengthwise of and below said hopper, and, communicating therewith, a plunger reciprocable in said cylinder, a. crank shaft operatively connected to said plunger, an oscillable countershaft extending parallel to said crank shaft and a crank arm thereon, ratchet driving means connecting said two shafts, a crank arm rotatable from said motor and positioned at one side of said hopper, and a link connecting said two cranks.

Signed at Seattle, King County, IVashton, this 20th day or November, 1920.

A'DOLPH OUSDAHL. 

